Sickness come back at 20 weeks?!

So I didn't suffer that bad in early pregnancy, mostly just feeling sick in the evenings and only sometimes actually being sick then It disappeared at around 14 weeks... Now this week (nearly 21 weeks) I have been sick a few times out of no where and I feel so crap . I thought I had got off lightly.. obviously not. I have been feeling her move a bit more recently so I don't know if that's got anything to do with it.